Construction of recombinant Bacillus subtilis strains for polyhydroxyalkanoates synthesis

Plastic wastes are considered to be a worldwide environmental problem and demand for biodegradable plastics has become a highly visible issue. One of the most important characteristics of microbial polyesters is that they are thermoplastic with environmentally degradable properties. In this experiment, pSG703/pha RBC and pSG703/pha PQRBC were cloned and transformed into £p105 prophage-based Bacillus subtilis. Construction of recombinant Bacillus was only partially successful. The pha PQRBC genes from B. megaterium were cloned into B. subtilis 1A304 (£p105 MU331). The pha genes is stable in the absence of selective pressure because the prophage is covalently inserted, in a single copy, into the host chromosome. The B. subtills 1A304 (£p105 MU331) carrying the pha genes (pha PQRBC) was subjected to fermentation and showed PHA accumulation, which was the first report of the expression of the pha genes of B. megaterium in B. subtilis. The cells was subjecDepartment of Applied Biology and Chemical TechnologyDepartment of Civil and Environmental Engineerin